Most guidelines recommend the use of a vapor barrier when wrapping and isolating hypothermic patients from the environment, and this is especially important if the patient is wearing wet clothing. The vapor barrier will contain moisture evaporated from the wet clothes of the patient and increase the humidity. Once the humidity levels reach 100%, the evaporation and thereby the evaporative heat loss will stop. The theory is that the addition of a vapor barrier will reduce the amount of heat loss and contribute to more efficient rewarming of wet, hypothermic patients. We aim to investigate how much more efficient a wrapping model with active external rewarming is with the addition of a vapor barrier.

The study will use a crossover design on where research participants will undergo repetitions of the same scenario with different interventions in order to serve as their own control. The research participants will be healthy volunteers providing both oral and written consent.

We intend to perform the experiments in an outdoor laboratory in order to achieve the most realistic conditions possible. The experiments will be conducted in Hemsedal, Norway in our "Mountain Lab", a climate chamber built inside a snow cave.

Before the start of the experiment, the research participants will be positioned in a supine position in the snow cave on an insulated stretcher in wet clothes saturated with a standardized amount of water.

Inclusion Criteria:

• healthy volunteers

Exclusion Criteria:

• any cronic sickness